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Viegas LP. A Multiconformational Transition State Theory Approach to OH Tropospheric Degradation of Fluorotelomer Aldehydes. Chemphyschem 2023; 24:e202300259. [PMID: 37326576 DOI: 10.1002/cphc.202300259] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 06/17/2023]
Abstract
Experimental work on the OH-initiated oxidation reactions of fluorotelomer aldehydes (FTALs) strongly suggests that the respective rate coefficients do not depend on the size of the Cx F2x+1 fluoroalkyl chain. FTALs hence represent a challenging test to our multiconformer transition state theory (MC-TST) protocol based on constrained transition state randomization (CTSR), since the calculated rate coefficients should not show significant variations with increasing values of x ${x}$ . In this work we apply the MC-TST/CTSR protocol to thex = 2 , 3 ${x={\rm 2,3}}$ cases and calculate both rate coefficients at 298.15 K with a value ofk = ( 2 . 4 ± 1 . 4 ) × 10 - 12 ${k=(2.4\pm 1.4)\times {10}^{-12}}$ cm3 molecule-1 s-1 , practically coincident with the recommended experimental value of kexp =( 2 . 8 ± 1 . 4 ) × 10 - 12 ${(2.8\pm 1.4)\times {10}^{-12}}$ cm3 molecule-1 s-1 . We also show that the use of tunneling corrections based on improved semiclassical TST is critical in obtaining Arrhenius-Kooij curves with a correct behavior at lower temperatures.
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Affiliation(s)
- Luís P Viegas
- Coimbra Chemistry Centre-Institute of Molecular Sciences (CQC-IMS), Department of Chemistry, University of Coimbra, 3004-535, Coimbra, Portugal
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2
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Viegas LP. Gas-phase OH-oxidation of 2-butanethiol: Multiconformer transition state theory rate constant with constrained transition state randomization. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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3
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Viegas LP. Simplified Protocol for the Calculation of Multiconformer Transition State Theory Rate Constants Applied to Tropospheric OH-Initiated Oxidation Reactions. J Phys Chem A 2021; 125:4499-4512. [PMID: 33902279 DOI: 10.1021/acs.jpca.1c00683] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chemical kinetics plays a fundamental role in the understanding and modeling of tropospheric chemical processes, one of the most important being the atmospheric degradation of volatile organic compounds. These potentially harmful molecules are emitted into the troposphere by natural and anthropogenic sources and are chemically removed by undergoing oxidation processes, most frequently initiated by reaction with OH radicals, the atmosphere's "detergent". Obtaining the respective rate constants is therefore of critical importance, with calculations based on transition state theory (TST) often being the preferred choice. However, for molecules with rich conformational variety, a single-conformer method such as lowest-conformer TST is unsuitable while state-of-the-art TST-based methodologies easily become unmanageable. In this Feature Article, the author reviews his own cost-effective protocol for the calculation of bimolecular rate constants of OH-initiated reactions in the high-pressure limit based on multiconformer transition state theory. The protocol, which is easily extendable to other oxidation reactions involving saturated organic molecules, is based on a variety of freeware and open-source software and tested against a series of oxidation reactions of hydrofluoropolyethers, computationally very challenging molecules with potential environmental relevance. The main features, advantages and disadvantages of the protocol are presented, along with an assessment of its predictive utility based on a comparison with experimental rate constants.
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Affiliation(s)
- Luís P Viegas
- Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, Buildings 1630-1632, Aarhus 8000, Denmark
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Medeiros DJ, Blitz MA, Seakins PW. Exploring the features on the OH + SO 2 potential energy surface using theory and testing its accuracy by comparison to experimental data. Phys Chem Chem Phys 2018; 20:8984-8990. [PMID: 29557461 DOI: 10.1039/c8cp00091c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ab initio theory has been used to identify the pre-reaction complex in the atmospherically important reaction between OH + SO2, (R1), where the binding energy of the pre-reaction complex was determined to be 7.2 kJ mol-1. Using reaction rate theory, implemented with the master equation package MESMER, the effects of this complex on the kinetics of R1 at temperatures above 250 K have been investigated. From simulations and fitting to the experimental kinetic data, it is clear that the influence of this pre-reaction complex is negligible and that the kinetics are controlled by the inner transition-state that leads to the product, HOSO2. While the effect of this complex on the thermal kinetics is small it potentially provides an efficient route to remove energy from vibrationally excited OH. The fitting to the past experimental data reveals that this inner transition-state is submerged with a barrier -0.25 kJ mol-1 below the entrance channel, which is outside the range predicted from the best theoretical calculations. The data fitting also yielded ΔR1H0K equal to -(109 ± 5.6) kJ mol-11 and a more precise expression for k∞1(T), (5.95 ± 0.83) × 10-13 × (T/298)-0.11±0.27.
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Affiliation(s)
- D J Medeiros
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - M A Blitz
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK. and National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, UK
| | - P W Seakins
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK. and National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, UK
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Winiberg FAF, Percival CJ, Shannon R, Khan MAH, Shallcross DE, Liu Y, Sander SP. Reaction kinetics of OH + HNO3 under conditions relevant to the upper troposphere/lower stratosphere. Phys Chem Chem Phys 2018; 20:24652-24664. [DOI: 10.1039/c8cp04193h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Key upper atmosphere reaction of HNO3 + OH studied over extended pressure and temperature range using new alternative detection method.
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Affiliation(s)
| | - Carl J. Percival
- NASA Jet Propulsion Laboratory
- California Institute of Technology
- Pasadena
- USA
| | - Robin Shannon
- School of Chemistry
- Cantock's Close
- University of Bristol
- Bristol
- UK
| | - M. Anwar H. Khan
- School of Chemistry
- Cantock's Close
- University of Bristol
- Bristol
- UK
| | | | - Yingdi Liu
- NASA Jet Propulsion Laboratory
- California Institute of Technology
- Pasadena
- USA
| | - Stanley P. Sander
- NASA Jet Propulsion Laboratory
- California Institute of Technology
- Pasadena
- USA
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6
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Zhu L, Sangwan M, Huang L, Du J, Chu LT. Photolysis of Nitric Acid at 308 nm in the Absence and in the Presence of Water Vapor. J Phys Chem A 2015; 119:4907-14. [DOI: 10.1021/acs.jpca.5b00951] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lei Zhu
- Wadsworth
Center, New York
State Department of Health, Department of Environmental Health Sciences, SUNY-Albany, Albany, New York 12201, United States
| | - Manuvesh Sangwan
- Wadsworth
Center, New York
State Department of Health, Department of Environmental Health Sciences, SUNY-Albany, Albany, New York 12201, United States
| | - Li Huang
- Wadsworth
Center, New York
State Department of Health, Department of Environmental Health Sciences, SUNY-Albany, Albany, New York 12201, United States
| | - Juan Du
- Wadsworth
Center, New York
State Department of Health, Department of Environmental Health Sciences, SUNY-Albany, Albany, New York 12201, United States
| | - Liang T. Chu
- Wadsworth
Center, New York
State Department of Health, Department of Environmental Health Sciences, SUNY-Albany, Albany, New York 12201, United States
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Petit AS, Harvey JN. Atmospheric hydrocarbonactivation by the hydroxyl radical: a simple yet accurate computational protocol for calculating rate coefficients. Phys Chem Chem Phys 2012; 14:184-91. [DOI: 10.1039/c1cp21367a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Kłos JA, Lique F, Alexander MH, Dagdigian PJ. Theoretical determination of rate constants for vibrational relaxation and reaction of OH(XΠ2,v=1) with O(P3) atoms. J Chem Phys 2008; 129:064306. [DOI: 10.1063/1.2957901] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Spectroscopic identification and stability of the intermediate in the OH + HONO2 reaction. Proc Natl Acad Sci U S A 2008; 105:12678-83. [PMID: 18678905 DOI: 10.1073/pnas.0800320105] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The reaction of nitric acid with the hydroxyl radical influences the residence time of HONO(2) in the lower atmosphere. Prior studies [Brown SS, Burkholder JB, Talukdar RK, Ravishankara AR (2001) J Phys Chem A 105:1605-1614] have revealed unusual kinetic behavior for this reaction, including a negative temperature dependence, a complex pressure dependence, and an overall reaction rate strongly affected by isotopic substitution. This behavior suggested that the reaction occurs through an intermediate, theoretically predicted to be a hydrogen-bonded OH-HONO(2) complex in a six-membered ring-like configuration. In this study, the intermediate is generated directly by the association of photolytically generated OH radicals with HONO(2) and stabilized in a pulsed supersonic expansion. Infrared action spectroscopy is used to identify the intermediate by the OH radical stretch (nu(1)) and OH stretch of nitric acid (nu(2)) in the OH-HONO(2) complex. Two vibrational features are attributed to OH-HONO(2): a rotationally structured nu(1) band at 3516.8 cm(-1) and an extensively broadened nu(2) feature at 3260 cm(-1), both shifted from their respective monomers. These same transitions are identified for OD-DONO(2). Assignments of the features are based on their vibrational frequencies, analysis of rotational band structure, and comparison with complementary high level ab initio calculations. In addition, the OH (v = 0) product state distributions resulting from nu(1) and nu(2) excitation are used to determine the binding energy of OH-HONO(2), D(0) <or= 5.3 kcal x mol(-1), which is in good accord with ab initio predictions.
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Carr SA, Baeza-Romero MT, Blitz MA, Price BJS, Seakins PW. Ketone photolysis in the presence of oxygen: A useful source of OH for flash photolysis kinetics experiments. INT J CHEM KINET 2008. [DOI: 10.1002/kin.20330] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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McCabe DC, Rajakumar B, Marshall P, Smith IWM, Ravishankara AR. The relaxation of OH (v=1) and OD (v=1) by H2O and D2O at temperatures from 251 to 390 K. Phys Chem Chem Phys 2006; 8:4563-74. [PMID: 17047754 DOI: 10.1039/b609330b] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report rate coefficients for the relaxation of OH(v=1) and OD(v=1) by H2O and D2O as a function of temperature between 251 and 390 K. All four rate coefficients exhibit a negative dependence on temperature. In Arrhenius form, the rate coefficients for relaxation (in units of 10(-12) cm3 molecule-1 s-1) can be expressed as: for OH(v=1)+H2O between 263 and 390 K: k=(2.4+/-0.9) exp((460+/-115)/T); for OH(v=1)+D2O between 256 and 371 K: k=(0.49+/-0.16) exp((610+/-90)/T); for OD(v=1)+H2O between 251 and 371 K: k=(0.92+/-0.16) exp((485+/-48)/T); for OD(v=1)+D2O between 253 and 366 K: k=(2.57+/-0.09) exp((342+/-10)/T). Rate coefficients at (297+/-1 K) are also reported for the relaxation of OH(v=2) by D2O and the relaxation of OD(v=2) by H2O and D2O. The results are discussed in terms of a mechanism involving the formation of hydrogen-bonded complexes in which intramolecular vibrational energy redistribution can occur at rates competitive with re-dissociation to the initial collision partners in their original vibrational states. New ab initio calculations on the H2O-HO system have been performed which, inter alia, yield vibrational frequencies for all four complexes: H2O-HO, D2O-HO, H2O-DO and D2O-DO. These data are then employed, adapting a formalism due to Troe (J. Troe, J. Chem. Phys., 1977, 66, 4758), in order to estimate the rates of intramolecular energy transfer from the OH (OD) vibration to other modes in the complexes in order to explain the measured relaxation rates-assuming that relaxation proceeds via the hydrogen-bonded complexes.
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Affiliation(s)
- D C McCabe
- NOAA Aeronomy Laboratory, 325 Broadway R/AL2, Boulder, Colorado 80305, USA.
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McCabe D, Smith I, Rajakumar B, Ravishankara A. Rate coefficients for the relaxation of OH (v=1) by O2 at temperatures from 204–371K and by N2O from 243–372K. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.01.037] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Khachatrian A, Dagdigian PJ. Effect of Vibrational Excitation on the Collisional Removal of Free Radicals by Atoms: OH(v=1) + N. J Phys Chem A 2006; 110:3388-92. [PMID: 16526617 DOI: 10.1021/jp0561017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The collisional removal of vibrationally excited OH(upsilon=1) by N(4S) atoms is investigated. The OH radical was prepared by 193 nm photolysis of H2O2, and N(4S) atoms were generated by a microwave discharge in N2 diluted in argon. The concentrations of OH(upsilon=0 and 1) were monitored by laser-induced fluorescence as a function of the time after the photolysis laser pulse. The N(4S) concentration was determined from the OH(upsilon=0) decay rate, using the known rate constant for the OH(upsilon=0) + N(4S) --> H + NO reaction. From comparison of the OH(upsilon=0 and 1) decay rates, the ratio of the rate constant k(upsilon=1)(OH-N) for removal of OH(upsilon=1) in collisions with N(4S) and the corresponding OH(upsilon=0) rate constant, k(upsilon=0)(OH-N) was determined to be 1.61 +/- 0.42, yielding k(upsilon=1)(OH-N) = (7.6 +/- 2.1) x 10(-11) cm3 molecule(-1) s(-1), where the quoted uncertainty (95% confidence limits) includes the uncertainty in k(upsilon=0)(OH-N). Thus, the collisional removal of OH(upsilon=1) by N(4S) atoms is found to be faster than for OH(upsilon=0).
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Affiliation(s)
- Ani Khachatrian
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218-2685, USA
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Huber JR. Photochemistry of Molecules Relevant to the Atmosphere: Photodissociation of Nitric Acid in the Gas Phase. Chemphyschem 2004; 5:1663-9. [PMID: 15580925 DOI: 10.1002/cphc.200400071] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This Minireview gives an account of the photochemical decay of nitric acid HNO3 in the gas phase, which has been well investigated under bulk and molecular-beam conditions. Due to the importance of this molecule in atmospheric chemistry, attention was paid to the irradiation regions around 300 and 200 nm, where solar photolysis of HNO3 is expected to be particularly efficient. While the low-energy region is characterized by the products OH and NO2, the high-energy region gives rise to a variety of photochemical decay pathways, dominated by channels which lead to the products HONO + O in different electronic states.
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Affiliation(s)
- J Robert Huber
- Physikalisch-Chemisches Institut der Universität Zürich, Winterthurerstrasse 190, 8507 Zürich, Switzerland.
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Vakhtin AB, McCabe DC, Ravishankara AR, Leone SR. Low-Temperature Kinetics of the Reaction of the OH Radical with Hydrogen Peroxide. J Phys Chem A 2003. [DOI: 10.1021/jp030424q] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrei B. Vakhtin
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, NOAA Aeronomy Laboratory, 325 Broadway R/AL2, Boulder, Colorado 80305, and Department of Chemistry and Biochemistry and CIRES, University of Colorado, Boulder, Colorado 80309
| | - David C. McCabe
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, NOAA Aeronomy Laboratory, 325 Broadway R/AL2, Boulder, Colorado 80305, and Department of Chemistry and Biochemistry and CIRES, University of Colorado, Boulder, Colorado 80309
| | - A. R. Ravishankara
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, NOAA Aeronomy Laboratory, 325 Broadway R/AL2, Boulder, Colorado 80305, and Department of Chemistry and Biochemistry and CIRES, University of Colorado, Boulder, Colorado 80309
| | - Stephen R. Leone
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309, NOAA Aeronomy Laboratory, 325 Broadway R/AL2, Boulder, Colorado 80305, and Department of Chemistry and Biochemistry and CIRES, University of Colorado, Boulder, Colorado 80309
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Affiliation(s)
- Ian W M Smith
- School of Chemical Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
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